1. Technical Field
The disclosed embodiments relate to power supply modules, and more particularly to a power supply module with a feedback circuit and a filtering circuit.
2. Description of Related Art
A power supply module is typically used to receive and process an alternating current (AC) voltage from an external power source, and generate a first direct current (DC) voltage to power an electronic device.
Generally, this kind of power supply module includes an AC/DC converter, a voltage transforming circuit, and a feedback circuit. The AC/DC converter is used for converting the AC voltage to a primary DC voltage. The voltage transforming circuit includes a transformer. The voltage transforming circuit is used for transforming the primary DC voltage to the first DC voltage. The feedback circuit is used for sampling a current flowing through a primary winding of the transformer to generate a feedback signal. The voltage transforming circuit maintains the first DC voltage at a predetermined value according to the feedback signal.
However, sometimes the feedback circuit can generate a surge voltage due to electromagnetic interference. The surge voltage is sometimes transmitted to the voltage transforming circuit and may damage the voltage transforming circuit.
What is needed, therefore, is a power supply module to overcome the above described limitations.